Funds are requested to purchase a new generation, highly sensitive isothermal titration calorimeter. This instrument will replace older models currently on campus. A major benefit of the new instrument will be the requirement for smaller reaction volumes and thus less material. The lower sample requirements will permit those investigators currently performing calorimetry to expand their studies, and lower the entry barrier for those investigators interested in thermodynamic quantities and calorimetry but hindered by the large sample requirements of the instruments presently available. Investigators who will particularly benefit include those studying proteins difficult to obtain in large quantities and/or studying interactions involving molecules prepared via synthetic organic chemistry. The instrument will be placed in a staffed core facility, ensuring its long term operational success.